Elastase secreted by activated polymorphonuclear leucocytes causes chondrocyte damage and matrix degradation in intact articular cartilage: escape from inactivation by alpha-1-proteinase inhibitor

Anatomically intact, murine patellar cartilage was exposed to human polymorphonuclear leucocytes (PMN) stimulated with formyl-methionyl-leucyl-phenylalanine or Ca-ionophore A-23187. This resulted in an inhibition of chondrocyte proteoglycan synthesis and breakdown of cartilage matrix proteoglycans as shown with 35S-incorporation and autoradiography. These effects could not be inhibited by catalase or superoxide dismutase. A serine protease inhibitor and a specific elastase inhibitor prevented both proteoglycan degradation and chondrocyte damage, indicating that PMN-elastase is the causative agent. It was shown that elastase shed by PMN in close contact with the articular cartilage, can escape from complexing with alpha-1 proteinase inhibitor. We would hypothesize that the elastase owing to its dual action (matrix breakdown and inhibition of chondrocyte metabolism) is a major contributor to enzymatic cartilage destruction in inflammatory disorders.     

Elastase from polymorphonuclear leucocytes: a regulatory enzyme in immune complex disease.

In sputa of 21 cystic fibrosis patients suffering from chronic Pseudomonas aeruginosa lung infections, activities of lysosomal proteases released from polymorphonuclear leukocytes (PMN) and immune complexes were quantitatively determined. The results showed that low immune complex values correlated with high protease activities and vice versa. In a longitudinal study fluctuating, reciprocal changes of the parameters were observed. Therefore, the hypothesis was investigated as to whether PMN elastase cleaves immune complexes and regulates inflammation. It was shown that treatment of immune complex-positive sputa with PMN elastase decreased IgG and IgA immune complex values and lead to cleavage of the immunoglobulins in the hinge region. PMN elastase-treated samples were not able to stimulate the oxidative burst of PMN. Cleavage of in vitro built immune complexes did not lead to liberation of bound antigen. Western blot analysis of one sputum sample revealed split products of the IgG heavy chain. The results suggest that PMN elastase splits off the Fc portion of immunoglobulins in immune complexes and thus regulates inflammation by a feedback mechanism leading to cyclic inflammatory states.     

Immunorecognition of chondrocytes in articular cartilage activated by synovial interleukin 1.

A polyclonal antiserum which recognizes surface epitopes on IL1-activated pig chondrocytes has been used to immunolocalize chondrocytes responding to IL1 produced during co-culture of pig synovium and articular cartilage. Activation of the chondrocytes by the cytokine was restricted to the articular and subarticular region of the cartilage adjacent to the synovium. Chondrocyte activation was also seen when human rheumatoid synovium was co-cultured with the cartilage. The presence of IL1 in some synovial cells was confirmed by immunolocalization using antisera specific for IL1 alpha and IL1 beta.     

The main serum protease inhibitors; alpha-1-proteinase inhibitor and alpha-2-macroglobulin inhibit H2O2 release from human polymorphonuclear leukocytes stimulated with phorbol myristate acetate.

Since various functions of phagocytes can be affected by protease inhibitors, the ability of alpha-1-proteinase inhibitor (alpha 1PI) and alpha-2-macroglobulin (alpha 2M) to modulate the H2O2 production by human polymorphonuclear leukocytes (PMNL) was studied. The preincubation of PMNL for 30 min with these protease inhibitors at concentrations which may occur in human blood diminished in a dose dependent manner their H2O2 generation induced with phorbol myristate acetate. At alpha 1PI 600 mg/dl and alpha 2M 800 mg/dl the H2O2 response decreased to 61 +/- 2 and 58 + 3% (p less than 0.001, n = 4) of the control value obtained with cells preincubated in phosphate buffered saline with glucose, respectively. Autologous serum alone and with addition of pure alpha 1 PI or alpha 2M also suppressed H2O2 release from PMNL. It is suggested that inhibition of H2O2 generation from PMNL may be another additional way by which these serum protease inhibitors may protect tissues (especially lungs) from acute injury related to inflammation.     

膝关节软骨中基质金属蛋白酶13及其组织抑制剂1的表达

背景：基质金属蛋白酶组织抑制剂1是与基质金属蛋白酶13相对应的拮抗剂,两者间表达水平和功能活性的平衡对细胞外基质的代谢状态起着重要作用,但在DH豚鼠骨关节炎发生发展过程中,两者表达水平,尤其两者表达水平比值的变化尚不明确。 目的：探讨不同月龄DH豚鼠关节软骨中基质金属蛋白酶13、基质金属蛋白酶组织抑制剂1表达比值的变化及其与DH豚鼠增龄性原发骨性关节炎发病过程中软骨退变程度的关系。 方法：选取2,4,8,12月龄雌性DH各6只,取膝关节观察关节软骨的大体形态后常规脱钙、包埋、制作石蜡切片,用于VG染色行组织学观察,采用Mankin评分系统定量分析关节软骨退变情况,采用免疫组织化学方法检测膝关节软骨中基质金属蛋白酶13、基质金属蛋白酶组织抑制剂1表达情况,应用 Image pro-Plus 6.0软件对免疫组织化学阳性蛋白表达情况进行积分吸光度计算。线性回归分析判断Mankin评分与基质金属蛋白酶13/基质金属蛋白酶组织抑制剂1比值的相关性。 结果与结论：DH豚鼠2月龄膝关节软骨无关节炎表现,4 月龄出现轻度软骨退变,并随月龄增加进行性加重,Mankin评分随月龄增加逐渐增高,各组之间的差异均有显著性意义(P < 0.05)。基质金属蛋白酶13、基质金属蛋白酶组织抑制剂1的表达均随月龄进行性增加,两者比值与Mankin评分呈正相关性(P < 0.05)。结果提示DH豚鼠4月龄出现膝关节软骨退行性变化,随月龄增加而进行性加重,其病理改变与基质金属蛋白酶13/基质金属蛋白酶组织抑制剂1表达失衡有关。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

Protease and elastase of Pseudomonas aeruginosa: inactivation of human plasma alpha 1-proteinase inhibitor.

The present study indicates that crystalline elastase of Pseudomonas aeruginosa is a very potent inactivator of human plasma alpha 1-proteinase inhibitor, the enzyme (E) inactivated the inhibitor (I) almost completely within 1 h at 25 degrees C at a molar ratio of E/I = 1:100. The crystalline P. aeruginosa protease also inactivated the inhibitor, but 100-fold less. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the alpha 1-proteinase inhibitor inactivated by the elastase and protease showed decreases in molecular weight of approximately 5,000 and 10,000, respectively. Regeneration of trypsin was negligible even when bovine trypsin-alpha 1-proteinase inhibitor complex (E/I = 1.0) was treated with the elastase. The affinity of alpha 1-proteinase inhibitor to trypsin was much higher than that to elastase. It was suggested that, assuming the pseudomonal proteases are produced and can inactivate alpha 1-proteinase inhibitor in vivo during pseudomonal diseases, the loss of alpha 1-proteinase inhibitor activity may permit the endogenous serine proteases to cause tissue destruction.     

Denaturation of type II collagen in articular cartilage in experimental murine arthritis. Evidence for collagen degradation in both reversible and irreversible cartilage damage

Degradation of type II collagen is thought to be a key step in the destruction of articular cartilage in patients with rheumatoid arthritis or osteoarthritis. The aim of this study was to investigate whether type II collagen degradation is associated with cartilage destruction. Type II collagen degradation was studied in two murine arthritis models, zymosan-induced arthritis (ZIA), which develops reversible articular cartilage damage based on proteoglycan analysis, and antigen-induced arthritis (AIA), in which there is irreversible damage to the cartilage. Type II collagen degradation was assayed immunohistochemically using the COL2-3/4m antibody which recognizes denatured type II collagen, such as is produced by collagenase cleavage. In both models, degradation of type II collagen was observed in the non-calcified articular cartilage of arthritic but not of control knees. In the patella-femoral compartment, collagen denaturation started to increase on day 3 (ZIA) and day 7 (AIA) and remained high on day 14. In contrast, in the tibia-femoral compartment, type II collagen breakdown was not increased before 14 days in either model. By 28 days, collagen denaturation was strongly reduced in the patella-femoral compartment in the ZIA model, but persisted in the tibia-femoral compartment in both models. In conclusion, increased type II collagen degradation was found in articular cartilage of both ZIA and AIA animals. Since ZIA does not develop irreversible cartilage destruction, this indicates that cartilage may have the ability to withstand a limited degree of type II collagen degradation without developing irreversible damage. Copyright © 1999 John Wiley & Sons, Ltd.     

维药买朱尼对骨关节炎大鼠模型关节软骨中基质金属蛋白酶1和基质金属蛋白酶抑制剂1的影响

背景：骨关节炎患者关节软骨的损害与基质金属蛋白酶1和基质金属蛋白酶抑制剂失平衡有关。 目的：观察基质金属蛋白酶1、基质金属蛋白酶抑制剂1在关节软骨中的表达及维药买朱尼对其影响。 方法：将20只SD大鼠采用改良Hulth造模法建立大鼠膝骨关节炎模型,按随机数字表法随机等分为买朱尼组和模型组,建模第2周开始分别灌胃维药买朱尼和生理盐水,连续4周。 结果与结论：相比于模型组,买朱尼组大鼠膝关节软骨退变程度减轻,软骨大体评分及Mankin评分降低(P < 0.05),且膝关节软骨细胞中基质金属蛋白酶1的表达降低,基质金属蛋白酶抑制剂1的表达增加(P < 0.05)。说明维药买朱尼可以通过下调基质金属蛋白酶1的表达水平、上调抑制剂的表达水平,对软骨产生保护作用。     

Enhanced tumor growth and invasiveness in vivo by a carboxyl-terminal fragment of alpha1-proteinase inhibitor generated by matrix metalloproteinases: a possible modulatory role in natural killer cytotoxicity

Matrix metalloproteinases (MMPs) are believed to contribute to the complex process of cancer progression. They also exhibit an alpha1-proteinase inhibitor (alphaPI)-degrading activity generating a carboxyl-terminal fragment of approximately 5 kd (alphaPI-C). This study reports that overexpression of alphaPI-C in S2-020, a cloned subline derived from the human pancreas adenocarcinoma cell line SUIT-2, potentiates the growth capability of the cells in nude mice. After stable transfection of a vector containing a chimeric cDNA encoding a signal peptide sequence of tissue inhibitor of metalloproteinase-1 followed by cDNA for alphaPI-C into S2-020 cells, three clones that stably secrete alphaPI-C were obtained. The ectopic expression of alphaPI-C did not alter in vitro cellular growth. However, subcutaneous injection of the alphaPI-C-secreting clones resulted in tumors that were 1.5 to 3-fold larger than those of control clones with an increased tendency to invasiveness and lymph node metastasis. These effects could be a result of modulation of natural killer (NK) cell-mediated control of tumor growth in nude mice, as the growth advantage of alphaPI-C-secreting clones was not observed in NK-depleted mice, and alphaPI-C-secreting clones showed decreased NK sensitivity in vitro. In addition, production of alphaPI and generation of the cleaved form of alphaPI by MMP were observed in various human tumor cell lines and in a highly metastatic subline of SUIT-2 in vitro. These results provide experimental evidence that the alphaPI-degrading activity of MMPs may play a role in tumor progression not only via the inactivation of alphaPI but also via the generation of alphaPI-C.     

Peritoneal macrophages which phagocytose autologous polymorphonuclear leucocytes in guinea-pigs. I: induction by irritants and microorgansisms and inhibition by colchicine.

In order to examine macrophages phagocytosing polymorphonuclear leucocytes (PMNs) in detail, we established a new method, whereby a large number of PMN-phagocytosing macrophages (PPMs) were easily induced. PPMs were harvested from the peritoneal cavity after thioglycollate medium, oyster glycogen, phytohaemagglutinin (PHA), L. monocytogenes or S. aureus had been injected i.p. into guinea-pigs. When thioglycollate medium or oyster glycogen was injected i.p., the number of the PPM reached a peak 48 h later and PPM formed 20% or more of total macrophages. When L. monocytogenes or S. aureus was injected i.p., the ratio of PPM to total macrophages reached a peak 24 h later. Morphologically, some of the phagocytosed PMNs were not degenerated and the others were at various stages of degeneration. The ability of macrophages to phagocytose PMNs was suppressed when 10(-6) mol/kg of colchicine was administered i.p. 1 day after the injection of the irritants.     

Prevention of tissue damage: Inhibition of Myeloperoxidase mediated inactivation of α1 inhibitor by N-acetyl cysteine,Glutathione, and Methionine

The ability of the sulphur compounds, N-acetyl cysteine, Methionine, and Glutathione to prevent inactivation of ₁ inhibitor by Myeloperoxidase-H₂O₂-Cl^–-system was investigated in vitro with purified components.The Myeloperoxidase system, or its main product HOCl by itself, readily abrogated the ability of ₁ inhibitor to inhibit elastase. This inactivation of ₁ inhibitor was effectively prevented by micromolar concentrations of N-acetyl cysteine, Methionine and reduced Glutathione, whereas oxidized Glutathione was much less effective. These results indicate that the sulphydryl compounds work as scavengers of the products of the Myeloperoxidase system, and might be useful in inflammatory disorders, to prevent tissue damage inflicted by this system.     

Rabbit models of arthritis: immunolocalization of matrix metalloproteinases and tissue inhibitor of metalloproteinase in synovium and cartilage.

The distribution of the matrix metalloproteinases, collagenase, stromelysin, gelatinases A and B, and the tissue inhibitor of metalloproteinases in cartilage and synovium removed from rabbits up to 27 days after induction of two models of arthritis was investigated by immunolocalization. Following intra-articular injection of poly-D-lysine/hyaluronic acid coacervate, collagenase and stromelysin were found bound to cartilage matrix, but there was little increase in chondrocyte synthesis of these enzymes. The synovium underwent a complex wound healing response involving invagination and encapsulation of the coacervate and inflammatory cell debris, during which all four metalloproteinases and tissue inhibitor of metalloproteinase could be immunolocalized. The second model, intra-articular injection of ovalbumin into sensitized rabbits, caused considerable chondrocyte necrosis; collagenase was found bound to cartilage matrix on day 13, although again there was little evidence of synthesis by chondrocytes. Inflammatory cell infiltration of meniscoid synovia took place initially, followed by fibrosis involving macrophagelike cells secreting gelatinase A. In both models there was rapid loss of glycosaminoglycan metachromasia from the cartilage matrix. These results are discussed in relation to current knowledge of metalloproteinase involvement in the chronic rheumatoid synovial pannus erosion of cartilage in humans. The data suggest that there are considerable differences between rheumatoid arthritis and these models, and their use must therefore be carefully defined.     

The induction of cell-associated and secreted IL-1 by iscoms, matrix or micelles in murine splenic cells.

The kinetics of the expression of membrane-associated IL-1 (mIL-1) and soluble IL-1 (sIL-1) was studied in in vitro stimulated spleen cells from non-primed mice or from mice primed with influenza virus antigens incorporated in the immuno-stimulating complexes (iscoms) or as micelles. Matrix, which is the carrier structure for the antigens in the iscom, was used as a non-antigen stimulus. The IL-1 produced was assayed in an IL-1-dependent cell line and the specificity was demonstrated in a blocking experiment with antiserum to IL-1 alpha. Soluble IL-1 alpha was also quantified in ELISA. Iscoms and matrix induced production of mIL-1 and sIL-1 in cultures from non-treated mice as well as from mice primed 4 days before with iscoms or micelles. Micelles were a less strong stimulus and did not induce production of sIL-1. Micelles induced production of mIL-1 in cultures from non-primed mice or from mice which were recently immunized with micelles. No mIL-1 expression was induced by micelles if the spleen cells originated from mice immunized shortly before with iscoms. Depletion experiments demonstrated that sIL-1 was produced by adherent cells upon stimulation with iscoms or matrix. However, factor(s) from the non-adherent cells seem to be necessary for optimal secretion of sIL-1.     

Metalloproteinase production by rabbit articular cartilage: comparison of the effects of interleukin-1α in vitro and in vivo

To assess the effects of interleukin-1 on intact articular cartilage in vitro, explants from young and adult rabbits were cultured with interleukin-1 and the distributions of the matrix metalloproteinases and tissue inhibitor of metalloproteinases (TIMP-1) were investigated by indirect immunofluorescence microscopy. One to 2-week-old cartilage chondrocytes synthesized collagenase in response to pure or crude interleukin-1 (monocyte conditioned medium), with subarticular cells most responsive. Collagenase synthesis was not stimulated in adult articular chondrocytes when explants were treated with either pure or crude interleukin-1. Stromelysin, gelatinase and TIMP-1 could not be demonstrated within any zone of the cartilage, indicating that their synthesis was not stimulated by either pure or crude interleukin-1. The addition of fibroblast growth factors, either alone or in combination with interleukin-1, did not modify these responses. These results contrast markedly with observations on cultured chondrocyte monolayers, where interleukin-1 treatment induces near co-ordinate expression of metalloproteinases. To assess the effects of interleukin-1 in vivo, it was injected into adult rabbit knee joint spaces and the articular cartilage subsequently analysed for evidence of altered metalloproteinase production by immunocytochemistry. No significant increase in metalloproteinase or TIMP-1 synthesis by chondrocytes was detected, although the cartilage matrix showed a marked loss of toluidine blue metachromasia. We conclude that metalloproteinases are not involved in the rapid loss of proteoglycan from cartilage matrix in these situations.     

Potency of antileukoprotease and alpha 1-antitrypsin to inhibit degradation of fibrinogen by adherent polymorphonuclear leukocytes from normal subjects and patients with chronic granulomatous disease.

We have studied the relative efficacy of antileukoprotease (ALP) and alpha 1-antitrypsin (alpha 1AT) to inhibit the degradation of substrate by polymorphonuclear leukocytes (PMN) attached onto a fibrinogen matrix. PMN elastase activity was assayed by radioimmunoassay of a specific 21-residue cleavage product from the amino terminus of the A alpha chain, A alpha (1-21), of fibrinogen. The adherence of PMN (1.0 x 10(6)) to a fibrinogen matrix was facilitated by incubation with recombinant tumor necrosis factor-alpha (1 nM). Subsequently, the cells were exposed to inhibitors before stimulation with cytochalasin B and formylmethionyl-leucylphenylalanine. Under these conditions, ALP inhibited A alpha (1-21) formation with an IC50 of 85 +/- 30 nM and alpha 1AT gave an IC50 of 220 +/- 98 nM (mean +/- SD). The effect of oxidant production on A alpha (1-21) formation was evaluated by comparing the effect of PMN from normal subjects with PMN from subjects with X-linked NADPH oxidase deficiency. Stimulation of PMN from the latter subjects in a similar fashion as described above resulted in the formation of 40 +/- 4 pmol/ml A alpha (1-21), or approximately twice the amount seen with cells from normal subjects. Preincubation with ALP or alpha 1AT in a concentration range between 10 to 900 nM resulted in an IC50 of 50 +/- 13 nM for ALP compared with 150 +/- 21 nM for alpha 1AT. Both inhibitors are more effective to prevent fibrinogen degradation caused by chronic granulomatous disease (CGD) PMN than by normal PMN despite the fact that CGD PMN generated more A alpha (1-21) than did normal PMN.(ABSTRACT TRUNCATED AT 250 WORDS)     

Membrane-type-1 matrix metalloproteinase, matrix metalloproteinase 2, and tissue inhibitor of matrix proteinase 2 in prostate cancer: identification of patients with poor prognosis by immunohistochemistry

Overexpression of the matrix metalloproteinase (MMP) 2 is associated with poor prognosis in many tumor types. Membrane-type-1 MMP (MMP14) activates MMP2 using pro-MMP2 specific inhibitor, tissue inhibitor of matrix proteinase 2 (TIMP2), as a receptor. We evaluated, by immunohistochemistry on 189 T3N0-2M0 prostate cancer (Pca) cases, the influence of MMP2, MMP14, and TIMP2 expression, individually and in association, on Pca disease-free survival (DFS). We evaluated marker expression separately in cancer, stromal, and benign epithelial (BE) cells according to a percentage scale (0%, <10%, 10%-50%, and >50%). Median follow-up was 4.61 years. In BE cells, there was an inverse relationship between initial prostate-specific antigen serum level and T3 stage with MMP14 expression (P = .003) and between pN stage and TIMP2 expression (P = .04). The most significant results with survival were obtained by dichotomizing the cases between those with less than 10% and at least 10% of cells expressing the marker, the latter category representing overexpression. TIMP2 overexpression in stromal cells was associated with a longer DFS with a hazard ratio of 0.573 (P = .02) for time to recurrence. MMP2 overexpression by BE cells correlated with a shorter DFS using a multivariate trend test (hazard ratio = 1.46, P = .02). Stromal cells expressing less than 10% TIMP2 and MMP2 overexpression was the only combination that was significantly associated with a shorter DFS (log-rank test, P = .0001). This study suggests that MMP14 is involved mostly in Pca implantation and that MMP2 and TIMP2 expression by reactive stromal cells might be used as predictors of DFS in T3N0-2M0 Pca.